Draft and damper regulator for furnaces.



Nn. 715,919. Patented Dec. le., |902.

l w. F. wlLMoTH. y

DRAFT AND DAMPEB REGULATUR FOR FURNACES.

(Application led Mar. 5, 1902.)

(No Model.)

UNITED STATES l PATENT OEEICE.

WILLIAM F. WILMOTH, OF NEW YORK, N. Y., ASSIGNOR TO AMERICAN FURNACECOMPANY,A OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

DRAFT AND DANIPER REGULATOR lFOR FURNACES.

SPECIFICATION forming part of Letters Patent No. 715,919, dated December16, 1902.

Application fled March 5, 1902.

To all whom, it may concern:

Beit known that I, WILLIAM FRANKLIN WILMOTH, a citizen of the UuitedStates, residing in New York, in the county and State of New York, haveinvented certain new and useful Improvements in Draft and DamperRegulators for Furnaces; and I do hereby declare the following to be afull, clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

My invention relates to improvements in draft and damper regulators forfurnaces; and it consists in means for automatically closing afurnace-damper when the re-door is opened, for automatically openingsuch damper to the fullest extent when theflredoor is again closed, andVthen for gradually moving the damper to a partially-closed position.

My invention consists also in the novel construction of thedamper-operatingdevice.

In the operation of furnaces it is highly important that the damper inthe furnaceoiftake shall be closed when the {ire-door is opened, so thatthe inrush of air, which would otherwise take place, may be prevented.Such inrush of air chills the heating-surface of the boiler and carriesaway a large amount of heat, besides subjecting parts of the boiler toconsiderable strain because of the sudden change of temperature. It isof coursenecessary that the damper shall be opened immediately' afterthe furnace-door is closed in order that the draftmay be restablished.When the fire is fresh, the damper should be open to the widest possibleextent; but after the fresh coal has become heated and partially cokedand the volatile constituent-s of the coal have been driven offconsiderable increase in economy maybe effected by partially closing thedamper in the furnace-otake, so as to decrease the draft. In practice itis found that the furnace attendants cannot be relied upon to operatesuch dampers by hand, and in practice no attention is paid to theopening and closing of the damper at the time of firing.

The objects of my invention are to increase serial no. 96,850. ino man.)

the efficiency of furnaces, to supply to a furnace only the quantity ofair required for goed combustion, and so to avoid the admission of anexcess of air, to close and open the furnace damper or dampers when thefire-door is opened or closed, to open the furnace-damper wide when thefire-door is first closed, and then to move such damper to apartially-closed position after the fresh fuel has become heated, and tomake the apparatus as simple, compact, reliable, and inexpensive aspossible.

I will now proceed to describe my invention with reference to theaccompanying drawings, in which one form of apparatus embodying myinvention is illustrated, and in which- Figure 1 is a front elevation ofa boiler, showing my improved damper-regulating apparatus in placethereon. Fig. 2 is a side View of such apparatus, and Fig. 3 is avertical sectional view of such apparatus.

In the drawings, 1 indicates the fire-door of a boiler-furnace; 2, theofftake thereof; 3, a damper in the offtake, provided with a 'weight 4tending to hold the same open normally, and 5 an arm by which saiddamper may be operated. The damper operating apparatus comprises ahydraulic cylinder and piston, the piston-rod of which is connected by acord or chain 6 to the said damper-operating arm '5, and suitable valvesregulating the flow of water to the said cylinder. 7 designates the saidcylinder, 8 the piston thereof, 9 the piston-rod, and l0 a tray uponsaid piston-rod adaptedto receive weights by means of which when thepiston is permitted to descend the damper may be pulled shut against theresistance of its weight 4. The piston-rod 9 projects through astufng-box on the lower end of the cylinder and is connected by means ofa bracket 11 to a valverod 12. Said valve-rod has a sliding connectionwith a sliding valve 13, mounted within a valve-casing 14, havingstuffing-boxes at both ends through which the said valve works. Suchsliding connection is produced by providing the valve-rod 12 with a head15 and entering the same within a bore 16 in the upper portion of thevalve closed by a cap 17. A pipe 18 connects the valve-casing 14 withany suitable source of Water-supply. Another pipe 19 connects saidvalve-casing with an orifice 2O near the bottom of the cylinder 7. Inthe valve 13 is a port 2l, which when opposite pipes 18 and 19 placesthe same in communication. Another pipe 22 connects the said orifice 20of the cylinder 7 with a valve 23, connected by a stem 24 to the pintleof the fire-door. This Valve 23 may he of the ordinary turn-plug typeand is arranged to be opened when the furnace-door is closed.

In Figs. 2 and 3 the parts are shown in the positions they would occupyif the furnacedoor has just been opened. The piston 8 is near the bottomof the cylinder 7, the damper is closed, the port 21 of the valve 13 isconnecting pipes 18 and 19, and the valve 23 is open, so that Waterflows from pipe 18 through pipes 19 and 22 and valve 23 to waste. If nowthe furnace-door be closed, valve 23 will be closed and the pressure ofthe Water entering the cylinder 7 from pipe 19 Will raise the pistou Sagainst the pressure of the Weights on its piston-rod, permitting thedamper to close. In its upward movement the piston overrides aleakage-port 25, which may be provided with any suitablelregulating-valve. When the piston is near the upper limit of its stroke,the head 15 of valve-rod 12 encounters the cap 17 of sliding valve 13and lifts the same, thus cutting oi the supply of Water. The weights onthe piston-rod 9 will then cause the piston to descend slowly, the rateof closing being determined by the rate of escape of water through theleakage-port 25,thusgradually moving the furnace-damper toward theclosed position until finally the piston overrides the leakage-port 25.This cuts o the escape of water, and the piston will then stand at suchposition until the firedoor is again opened. Vhen this takes place,valve 23 isopened, the Water in cylinder 7 beneath the piston ispermitted to escape to waste, the piston descends, thus closing thedamper, and as the piston nears the lower limit of its stroke the head15 of valve-rod 12 encounters the sliding valve 13'and pushes the latterdown, thus again turning on the water by which the device is operated.

Valve 23 constitutes the controlling device of the apparatus, and port25 constitutes a secondary controlling device or slow-closing means.

The action of the device may be regulated by regulating the rate atwhich Water may escape through leakage-port 25. The location of thisport determines what will be the normal position of the damper. Suchnormal position Will obviously be between the closed position and theWide-open position and will be the position best adapted for normaloperation. This avoids drawing into the Obviously the cylfurnace anexcess of air.

inder may be provided with a plurality of such leakage-ports located atdifferent heights,and thus by opening one or the other of these portsthe normal position of the damper may be regulated.

It :is obvious that my invention may be operated by other iluids underpressure besides water-such, for example, as steam or compressed air. ItWill be noted that since the valve 13 passes through both ends of thevalvecasing it is perfectly balanced and has no tendency to move ofitself.

It is obvious that my invention is susceptible of many modifications andchanges in construction and arrangement of the parts and in operationWithout departing from the basic principles of the invention, and I donot limit myself to the particular construction ot' the device hereinillustrated and described.

What I claim is- 1. In a damper-operating apparatus, the combinationwith a motor for operating a damper, adapted to open and close thedamper or to hold it in an intermediate position, of automaticcontrolling means for said motor arranged to cause the same to close thedamper, to open the same, and to move the same automatically to, andmaintain it at, an intermediate position subsequent to the openingthereof.

2. In a damper-operating apparatus, the combination with a motor foroperating a damper, adapted to open and close the damper or hold it atan intermediate position, of automatic controlling means for said motorarranged to cause the same to open and close the damper, and comprisingslow-closing means arranged to cause the motor, after each opening ofthe damper, to move the same gradually to a partially-closed positionand maintain it there.

3. In a damper-operating apparatus, the combination with a motor foroperating a damper, of primary and secondary controlling means therefor,the primary means arranged to cause said motor to operate to open orclose the damper, according to the Way said controlling means isoperated, the secondary controlling means arranged to cause said motor,after each closing of the damper, to move the same to an intermediateposition and to maintain it there.

4. In a damper operating apparatus, the combination with a chamberhaving valvecontrolled means for supplying fluid under pressure theretoand permitting exhaust of such fluid therefrom, and having alsosecondary escape means permitting relatively slow escape of Huidtherefrom While normal exhaust is prevented, of a movable Wall for saidchamber arranged to closesaid escape means at an intermediate point inits movement.

5. In a damper operating apparatus, the combination with a chamberhaving supply and exhaust valves and secondary escape IOO IIO

means permitting relatively slow escape of fluid therefrom while normalexhaust is prevented, of a movable wall for said chamber operating thesupply-valve and likewise arranged to close said escape means at anintermediate point in its movement.

6. In a damper-operating apparatus, the combination with a chamberhaving separate supply and exhaust valves and secondary escape meanspermitting relatively slow escape of fluid therefrom, While normalexhaust is prevented, of a movable Wall for said chamber operating thesupply-valve and likewise arranged to close said escape means at anintermediate point in its movement.

7. In a damper-operating apparatus, the combination with a cylinderhaving valvecontrolled means for supplying iiuid under pressure theretoand permitting exhaust of such fluid therefrom, and having alsosecondary escape means permitting relatively slow escape of iuidtherefrom while normal exhaust is prevented, of a piston for saidchamber arranged toiclose said escape means at an intermediate point inits movement.

8.l In a damper-operating apparatus, the combination with a cylinderhaving supply and exhaust valves and secondary escape means permittingrelatively slow escape of Huid therefrom While normal exhaust isprevented, of a piston for said cylinder operating the supply-valve andlikewise arranged to close said escape means at an intermediate point inits movement. y

9. In a damper-operating apparatus, the combination with a cylinderhaving separate supply and exhaust valves and a secondary escape-portpermitting relatively slow escape of iiuid therefrom while normalexhaust is prevented, of a piston for said cylinder operating thesupply-valve and likewise arranged to override and close saidvescape-port at an intermediate point in its movement.

10. In a damper-operating apparatus, the combination With a cylinder anda piston therefor, of supply and exhaust valves automatically operated,and a secondary escapeport which is open when the piston is at the outerend of `said cylinder and is overridden and closed by the piston duringits motion inward.

ll. In a damper-operating apparatus, the combination with a cylinder anda piston therefor, of supply and exhaust valves automatically operated,the former by the motion of the piston, and a secondary escape-portwhich is open when the piston is at the outer end of said cylinder andis overridden and closed by the piston during its motion inward.

12. In a damper-operating apparatus, the combination With a cylinder anda piston therefor, of supply and exhaust valves automatically operated',the latter arranged to be operated by connection to afurnace-door, and asecondary escape-port which is open when the piston is at the outer endof said cylinder and is overridden and closed by the piston during itsmotion inward.

13. The combination with a furnace, and a damper therefor, of adamper-operating apparatus comprising a damper-operating motor arrangedto open and close` said damper or to hold the same in an intermediateposition, and automatic controlling means for said motor arranged tocause the same to open and close the damper and move the latter to anintermediate position after each opening thereof.

14. The combination with a furnace, and a damper therefor, of adamper-operating apparatus comprising a damper-operating motor arrangedto open and close said damper or to hold the same in an intermediateposition, a controlling device for said motor automatically operated`upon the opening or closing of the furnace-door, and arranged to causesaid motor to close or open said damper according as the furnace-door isopened or closed, and secondary controlling means arranged to cause saidmotor to partly close the damper and hold the same in such position,after' each closing of the furnace-door.

In testimony whereof I afx my signature in the presence of twowitnesses.

WILLIAM F. WILMOTH.

/Vitnesses:

WILLIAM D. ADAMS, HARRY M. MARBLE.

